Field
Aspects relate to wireless communication systems that include a radio frequency (RF) mixer used to downconvert a RF signal to baseband in the receiver or to upconvert a baseband signal into an RF signal in the transmitter, and in a more particular aspect, to correcting imbalances between Inphase (I) and Quadrature (Q) (IQ or I/Q) components in an RF communication system having multiple receiver and/or transmitter RF elements.
Related Art
IQ modulation and demodulation are used in wireless communication systems to fully utilize all degrees of freedom in a radio frequency (RF) signal. Due to non-idealities in transceiver hardware, especially the mixer in the up- or down-conversion imbalances arise between the Inphase (I) and Quadrature (Q) components. The IQ components may have different mean amplitude or gain. In additional, the phase difference between the I and Q components may be off from the ideal quadrature difference of 90°. In additional to the mixer, these imbalances can exist both at a transmitter and a receiver, and can arise from effects such as phase and amplitude variation in clocking, trace difference in the IQ branches, as well as phase and amplitude variation in filtering for the I and Q branches of transmitters and receivers. Such imbalances can degrade the capabilities and performance of the communication system.